Non-aqueous washing apparatus and method

ABSTRACT

Methods for washing fabric loads without water or using water only as a co-solvent are disclosed. One method of non-aqueous clothes washing includes the steps of disposing clothing in a wash container, delivering a wash liquor to the fabric load, the wash liquor comprising a substantially non-reactive, non-aqueous, non-oleophilic, apolar working fluid and at least one washing additive, applying mechanical energy to the clothing and wash liquor for a sufficient amount of time to provide fabric cleaning and, thereafter, substantially removing the wash liquor from the fabric load. The working fluid may be selected from the group consisting of perfluorocarbons, hydrofluoroethers, fluorinated hydrocarbons and fluoroinerts.

This application is a Continuation of patent application Ser. No.10/027,160, Filed Dec. 20, 2001.

BACKGROUND OF THE INVENTION

The present invention generally relates to apparatus and methodsemployed in the home for laundering clothing and fabrics. Moreparticularly, it relates to a new and improved method and apparatus forhome laundering of a fabric load using a wash liquor comprising atwo-phase mixture of a substantially inert working fluid and at leastone washing additive.

As used herein, in the Specification and Claims, the terms“substantially non-reactive” or “substantially inert” when used todescribe a component of a wash liquor or washing fluid, means anon-solvent, non-detersive fluid that under ordinary or normal washingconditions, e.g. at pressures of −10 to 50 atmospheres and temperaturesof from about 10 to about 45 C, does not appreciably react with thefibers of the fabric load being cleaned, the stains and soils on thefabric load, or the washing additives combined with the component toform the wash liquor.

Home laundering of fabrics is usually performed in an automatic washingmachine and occasionally by hand. These methods employ water as themajor component of the washing fluid. Cleaning additives such asdetergents, enzymes, bleaches and fabric softeners are added and mixedwith the water at appropriate stages of the wash cycle to providecleaning, whitening, softening and the like.

Although improvements in automatic washing machines and in cleaningagent formulations are steadily being made, as a general rule,conventional home laundering methods consume considerable amounts ofwater, energy and time. Water-based methods are not suitable for somenatural fiber fabrics, such as silks, woolens and linens, so that wholeclasses of garments and fabrics cannot be home laundered, but instead,must be sent out for professional dry cleaning. During water washing,the clothes become saturated with water and some fibers swell and absorbwater. After washing, the water must be removed from the clothes.Typically, this is performed in a two-step process including a hard spincycle in the washer and a full drying cycle in an automatic dryer. Thehard spin cycles tend to cause wrinkling which is not wanted. Even afterspinning, drying cycle times are undesirably long.

Non-aqueous washing methods employed outside the home are known, but forvarious reasons, these methods are not suitable for home use. Generally,the non-aqueous washing methods to date employ substitute solvents inthe washing fluid for the water used in home laundering.

Conventional dry cleaning methods have employed halogenated hydrocarbonsolvents as a major component of a wash liquor. The most commonly usedhalogenated hydrocarbon solvents used for dry cleaning areperchloroethylene, 1,1,1-trichloroethane and CFC-113. These solvents areozone depleting and their use is now controlled for environmentalreasons. Moreover, many of these solvents are suspected carcinogens.Accordingly these dry cleaning solvents cannot be used in the home.

Alternative dry cleaning methods of have employed petroleum-based orStoddard solvents in place of the halogenated hydrocarbon solvents. Thepetroleum-based solvents are inflammable and smog-producing.Accordingly, their commercial use is problematic and use of thesematerials in the home is out of the question. U.S. Pat. No. 5,498,266describes a method using petroleum-based solvents whereinperfluorocarbon vapors are admixed with petroleum solvent vapors toremove the solvents from the fabrics and provide improvements in safetyby reducing the likelihood of ignition or explosion of the vapors.

A further non-aqueous solvent based washing method employs liquid orsupercritical carbon dioxide solvent as a washing liquid. As describedin U.S. Pat. No. 5,467,492, highly pressurized vessels are required toperform this washing method. In accordance with these methods, pressuresof about 500 to 1000 psi are required. Pressures of up to about 30 psiare approved for use in the home. The high pressure conditions employedin the carbon dioxide methods would amount to placing a bomb in the homewhich is clearly unworkable.

Various perfluorocarbon materials have been employed alone or incombination with cleaning additives for washing printed circuit boardsand other electrical substrates, as described for example in U.S. Pat.No. 5,503,681. Spray cleaning of rigid substrates is very different fromlaundering soft fabric loads. Moreover, cleaning of electricalsubstrates is performed in high technology manufacturing facilitiesemploying a multi-stage apparatus which is not readily adapted for homeuse.

Accordingly, to overcome the disadvantages of prior art home launderingmethods, it is an object of the present invention to provide a new andimproved method and apparatus for laundering a fabric load in the homeemploying a safe and effective, environmentally-friendly, nonaqueouswash liquor.

It is another object of the present invention to provide a new andimproved apparatus for laundering a fabric load in the home, which issafe and effective for a broad range of fabric types, including naturalfiber fabrics, such as woolens, linens and silks.

It is a further object of the present invention to provide a new andimproved home laundering method and apparatus which consumes less water,time and energy than conventional water-based home laundering machinesand methods.

It is still another object of the present invention to provide a new andimproved dry to dry home laundering method and apparatus requiring lesshandling by the home user.

It is a further object of the present invention to provide a new andimproved home laundering method and apparatus which provides safe andeffective fabric cleaning without introducing wrinkling.

SUMMARY OF THE INVENTION

In accordance with these and other objects, the present inventionprovides a new and improved method and apparatus for laundering a fabricload in the home. In an embodiment, a method for laundering a fabricload is provided comprising the steps of:

-   -   disposing a fabric load in a wash container;    -   delivering a wash liquor to the fabric load, said wash liquor        comprising a substantially non-reactive, non-aqueous,        non-oleophilic, apolar working fluid and at least one washing        additive;    -   applying mechanical energy to provide relative movement between        said fabric load and said wash liquor for a time sufficient to        provide fabric cleaning; and    -   thereafter, substantially removing said wash liquor from said        fabric load.

In a preferred embodiment, the working fluid is a liquid under washingconditions and has a density of greater than 1.0. The working fluid hasa surface tension of less than or equal to 30 dynes. The oil solvency ofthe working fluid should be greater than water without being oleophilic.Preferably, the working fluid has an oil solvency as measured by KBvalue of less than or equal to 30. The working fluid, also has asolubility in water of less than about 10%. The viscosity of the workingfluid is less than the viscosity of water under ordinary washingconditions. The working fluid has a pH of from about 6.0 to about 8.0.Moreover, the working fluid has a vapor pressure less than the vaporpressure of water and has a flash point of greater than or equal to 145C. The working fluid is substantially non-reactive under washingconditions with fabrics in the fabric load, with the additives presentin the at least one washing additive and with oily soils and watersoluble soils in the fabric load.

The working fluid is substantially non-swelling to natural fabricspresent in the fabric load.

In an embodiment, the working fluid is a fluorine-containing compoundselected from the group consisting of: perfluorocarbons,hydrofluoroethers, fluorinated hydrocarbons and fluoroinerts.Preferably, the working fluid comprises a compound having the formula:(CF₃(CF₂)_(n))₃Nwherein n is an integer of from 4 to 20.

In an embodiment, the at least one washing additive may be selected fromthe group consisting of: surfactants, enzymes, bleaches, ozone,ultraviolet light, hydrophobic solvents, hydrophilic solvents,deodorizers, fragrances, antistatic agents and anti-stain agents.Mixtures of any of these washing additives may be used. A number ofwashing additives may be individually mixed with working fluid and thesemixtures may be sequentially contacted with the fabric load in anydesired order.

In an embodiment relative movement between the fabric load and washliquor is provided by moving the wash container in a manner which movesthe fabric load with respect to the wash liquor. Relative movement maybe provided by rotating the wash container about a horizontal axis or byrotating the wash container about a vertical axis. Relative movement maybe provided by nutating the wash container about a vertical axis.Relative movement may also be provided by pumping the wash liquor fromthe wash container and respraying the wash liquor into the washcontainer, as well as, by high pressure jetting of the wash liquor intothe wash container. Vibratory shaking of the wash container may also beused to provide relative movement. Relative movement may be provided byexposing the wash container to ultra-sonic irradiation. Relativemovement may also be provided by moving an agitator within the washcontainer relative to the wash container, or by reciprocally partiallyrotating the wash container with respect to stator blades mounted in thewash container.

A preferred method for laundering a fabric load comprises the steps of:

-   -   disposing a fabric load in a wash container;    -   delivering a first amount of a substantially non-reactive,        non-aqueous, non-oleophilic, apolar working fluid to the fabric        load;    -   tumbling the fabric load and working fluid by rotating the wash        container about a horizontal axis for a first time period;    -   delivering at least one washing additive to the fabric load and        working fluid to provide a wash liquor comprising the working        fluid and the washing additive in the wash container;    -   tumbling the fabric load and wash liquor for a second time        period sufficient to provide fabric cleaning;    -   draining said wash liquor from the wash container while rotating        the wash container about a horizontal axis under soft spin        conditions of less than about 1 g; and    -   thereafter, introducing a flow of air through the wash container        and tumbling the fabric load in the air flow until removal of        any remaining wash liquor from the fabric load is substantially        complete.

Another preferred method for laundering a fabric load comprises thesteps of:

-   -   disposing a fabric load in an interior chamber of a wash        container;    -   pressurizing the chamber to an elevated pressure of between        about 15 atmospheres to about 50 atmospheres;    -   delivering a wash liquor to the fabric load in the pressurized        chamber in the form of a mist, said wash liquor comprising a        substantially non-reactive, non-aqueous, non-oleophilic, apolar        working fluid and at least one washing additive;    -   applying mechanical energy to provide relative movement between        the fabric load and the mist for a time sufficient to provide        fabric cleaning;    -   decreasing the pressure in the chamber to volatilize the wash        liquor; and    -   removing the volatilized wash liquor from the chamber and fabric        load.

In an embodiment, the present invention also provides a new and improvedautomatic washing apparatus for dry to dry laundering of a fabric loadin the home, said apparatus comprising:

-   -   a housing;    -   a wash container in the housing having an inner washing cavity        defined therein mounted for rotational movement about a        horizontal axis, said wash container including a reclosable        opening permitting insertion and removal of a fabric load to and        from the washing cavity, a liquid inlet communicating with the        washing cavity, a liquid outlet communicating with the washing        cavity, a gas inlet communicating with the washing cavity and a        gas outlet communicating with the washing cavity;    -   a condenser mounted in the housing fluidly connected to the gas        outlet including an exhaust outlet and a liquid condensate        outlet;    -   a working fluid storage vessel mounted in the housing for        providing a supply of a substantially non-reactive, non-aqueous,        non-oleophilic apolar working fluid disposed therein, said        working fluid storage vessel including a working fluid outlet        fluidly connected to the liquid inlet and a working fluid inlet;    -   a gravimetric liquid separation vessel mounted in the housing,        including a wash liquor inlet fluidly connected to the liquid        outlet, a liquid condensate inlet fluidly connected to the        liquid condensate outlet and a working fluid outlet fluidly        connected to the working fluid inlet;    -   means for dispensing at least one washing additive to the        washing cavity;    -   means for moving working fluid from the working fluid storage        vessel to the washing cavity;    -   means for moving wash liquor from the liquid outlet to the        gravimetric liquid separation vessel;    -   means for sensing a boundary between said at least one washing        additive and the working fluid in the gravimetric liquid        separation vessel;    -   means for moving separated working fluid in the gravimetric        liquid separation vessel to the working fluid inlet;    -   means for introducing a flow of air in the washing cavity from        the gas inlet to the gas outlet; and    -   means for rotating the wash container.

In an alternate embodiment, the present invention provides an automaticwashing apparatus for dry to dry laundering of a fabric load in thehome, said apparatus comprising:

-   -   a sealed pressurizable wash container;    -   means for pressurizing the wash chamber to pressures of from        about 5 atm to about 50 atm;    -   a wash basket disposed in the wash chamber for receiving a        fabric load;    -   means for dispensing a wash liquor having a vapor pressure less        than the vapor pressure of water onto the fabric load at a first        pressure of between 1 atm and 50 atm;    -   means for agitating the wash liquor and fabric load in the wash        basket;    -   means for substantially removing the wash liquor from the wash        basket; and    -   means for reducing the pressure in the wash container to a        reduced second pressure less than the first pressure to remove        any remaining wash liquor from the fabric load in vapor form.        Preferably the wash liquor is dispensed in the form of a mist.        The fabric load may be arranged on hangers in accordance with        this embodiment.

A major advantage provided by the present invention is that it conservestime, water and energy.

Another advantage provided by the present invention is that a dryer isnot required, saving cost, energy and floor space.

A further advantage provided by the present invention is that thepreferred apparatus does not employ a hard spin cycle and eliminates theneed for a dryer so that home laundering methods and apparatus areprovided which are less noisy.

Still another advantage provided by the present invention is that lesssorting, transferring and handling of the fabric load is required by thehomeowner.

A further advantage provided by the present invention is that homelaundering in accordance with the invention is substantiallynon-wrinkling so that no ironing is needed.

Still another advantage provided by the present invention is thatbecause the wash liquor is non-wetting to the fabric load, no hard spincycle is required, which in turn permits a washer to be provided whichdoes not need a suspension system, thereby reducing cost, weight andenergy.

A further advantage provided by the present invention is that cleaningof wool, silk and linen in the home is provided for the first time.

Other objects and advantages of the present invention will becomeapparent from the following detailed description of the PreferredEmbodiments, taken in conjunction with the drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail, with reference tothe accompanying drawings, in which:

FIG. 1 is a perspective view of a combined washing apparatus and workingfluid storage unit made in accordance with the present invention;

FIG. 2 is a schematic diagram of a washing apparatus and ideal workingfluid storage unit made in accordance with the present invention;

FIG. 3 is a schematic diagram of another embodiment of a washingapparatus and ideal working fluid storage unit made in accordance withthe present invention;

FIG. 4 is a flow chart illustrating a non-aqueous method of laundering afabric load in accordance with the present invention;

FIG. 5 is a flowchart illustrating another non-aqueous method oflaundering a fabric load in accordance with the present invention;

FIG. 6 is a flowchart illustrating another non-aqueous method oflaundering a fabric load in accordance with the present invention;

FIG. 7 is a flowchart illustrating another non-aqueous method oflaundering a fabric load in accordance with the present invention;

FIG. 8 is a flowchart illustrating another non-aqueous method oflaundering a fabric load in accordance with the present invention;

FIG. 9 is a flowchart illustrating another non-aqueous method oflaundering a fabric load in accordance with the present invention;

FIG. 10 is a flowchart illustrating another non-aqueous method oflaundering a fabric load in accordance with the present invention;

FIG. 11 is a flowchart illustrating another non-aqueous method oflaundering a fabric load in accordance with the present invention;

FIG. 12 is a flowchart illustrating another non-aqueous method oflaundering a fabric load in accordance with the present invention;

FIG. 13 is a perspective view of another washing apparatus made inaccordance with the present invention; and

FIG. 14 is a partial view of the washing apparatus shown in FIG. 13.

It should be understood that the drawings are not necessarily to scaleand that the embodiments are sometimes illustrated by graphic symbols,phantom lines, diagrammatic representations and fragmentary views. Incertain instances, details which are not necessary for an understandingof the present invention or which render other details difficult toperceive may have been omitted. It should be understood, of course, thatthe invention is not necessarily limited to the particular embodimentsillustrated herein.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

An apparatus 10 for carrying out the method of laundering fabric loadsin accordance with the present invention is illustrated. The apparatus10 includes a washing apparatus 11 disposed adjacent to a working fluidstorage unit 12. The washing apparatus 11 includes a front door 13,preferably with a handle 14, for placing a fabric load (not shown) inthe washer 11. A control panel 15 is disposed along the top of thewasher 11, preferably along a back edge.

As illustrated in FIG. 2, the washing apparatus 11 includes a centrallydisposed wash chamber 16 which receives a fabric load (not shown).Working fluid is supplied to the wash chamber 16 from the working fluidstorage unit 12. The storage unit 12 includes a generally centrallydisposed tank 17 with an outlet conduit 18 and an inlet conduit 19. Inthe embodiment illustrated in FIG. 2, the working fluid is stored in theunit 12 in a gas form. Gaseous fluid passes through the outlet 18,through a filter 21 and through a three-way valve 22. When fluid is tobe charged into the wash chamber 16, the valve 22 is open betweenconduits 23 and 24 and gas flows through the valve 22 into acompressor/condenser 25. The gas is at least partially condensed in thecompressor/condensor 25 before it passes through a heater/cooler unit 26which, depending upon the working fluid, will most likely remove heatfrom the at least partially condensed gas stream so that the workingfluid is converted into a liquid form before entry into the wash chamber16.

The combination of the fabric (e.g. clothes) and the working fluid isthen preferably agitated within the chamber 16 by way of an agitationmeans (not shown in FIG. 2) for a relatively short time period comparedto currently-available automatic washers that use water as a workingfluid. After the wash cycle, a three-way valve 27 is opened so thatcommunication is established between conduits 28 and 29. A dischargepump 30, having already been activated, pumps the working fluid throughthe valve 27, through a conduit 32, and into a dirt container shown at33. In the dirt container 33, the working fluid is vaporized, leavingany dirt particles entrained in the fluid in the dirt container 33 andpermitting the gaseous working fluid to proceed through a conduit 34,through a filter 35, through the conduit 19 and back into the storagetank 17.

In an alternative apparatus 10 a illustrated in FIG. 3, a washingapparatus 11 is again disposed adjacent to a storage unit 12 which alsoincludes a storage tank 17 for containing the working fluid. However, inthe system 10 a, the working fluid has a lower vapor pressure atoperating pressures and temperature and, hence, is present within thestorage tank 17 primarily as a liquid. To charge the wash chamber 16,fluid flows out of the storage tank 17, through the conduit 18 andthrough the filter 21. Again, a three-way valve 22 is disposed betweenthe filter 21 and the wash chamber 16. In the embodiment 10 aillustrated in FIG. 3, the three-way valve 22 provides communicationbetween the conduit 23 and either a pump 48 for pumping the fluidthrough a three-way valve 36 and out a drain disposal 37 or, to afour-way valve shown at 38.

To charge the wash chamber 16 with working fluid, the four-way valve 38is opened providing communication between conduits 39 and 28, fluidentering the chamber 16 through the conduit 28. Preferably, the fabricload (not shown) and working fluid are tumbled or agitated for a fewminutes before additives are added to the chamber 16. Washing additivesare added to the chamber 16 by way of a dispenser 42 and recirculatedworking fluid being pumped by the pump 31, through the conduit 32,through the dispenser 42 and out a spray or mist port 43.

When washing additives are to be delivered to the washing chamber 16,the four-way valve 38 is opened so that communication is establishedbetween the conduit 28 and the conduit 29. The back flush/recirculationpump 31 then pumps the fluid through the conduit 32, through thedispenser 42 and out the delivery port 43. Additives that have beendisposed in the dispenser 42 are then entrained in the fluid beingrecirculated to the washing chamber 16 through the delivery port 43. Aperforated basket is preferably disposed within the chamber 16 whichpermits particles and lint material from the fabric to flow through theperforated walls of the basket before being collected under the force ofgravity in a particle/lint trap 45. A conduit 46 provides communicationbetween the chamber 16 and a heater/cooler 26 for controlling thetemperature of the working fluid within the chamber 16. The three-wayvalve 36, in a drain mode, establishes communication between a conduit48 and the conduit 37. The working fluid is not normally drained fromthe washing chamber 16. Instead, it is normally recirculated by way ofthe pathway defined by the conduit 28, four-way valve 38, conduit 29,pump 31, conduit 32, dispenser 42, conduit 34, filter 35 and conduit 19.

FIGS. 4-12 illustrate various methods of washing fabrics in accordancewith the present invention. For definitional purposes, a fluid thatpossesses no detersive properties similar to those properties found inconventional detergents, dry cleaning agents and liquefied carbondioxide will hereinafter be referred to as an ideal working fluid (IWF).Examples of IWFs that can be utilized with the methods and apparatusesof the present invention include fluoroinerts, hydrofluoroethers,perfluorocarbons and similarly fluorinated hydrocarbons.

Compounds that provide a detersive action that is required to removeparticulates, film soils and stains or that assist in the removal ofparticulates, film soils and stains will hereinafter be referred to asperformance enhancers. These compounds include enzymes, organic andinorganic bleaches, ozone, ultraviolet light or radiation as well aspolar and non-polar solvents.

A solvent that is different from the IWF in that its sole purpose is toprovide detersive properties not met by the performance enhancers willhereinafter be referred to as a co-solvent. Co-solvents that may be usedin the methods and with the apparatuses of the present invention includealcohols, ethers, glycols, esters, ketones and aldehydes. A mixture ofthese co-solvents with the IWF provides a system that is sufficientlystable for a fabric washing application.

Turning to FIG. 4, a first step 60 in one method of practicing thepresent invention is the loading of the washing chamber shown at 16 inFIGS. 2 and 3. The chamber 16 should preferably be capable of tumbling,agitating, nutating or otherwise applying mechanical energy to thecombination of the fabrics and the IWF. A next step 61 includes theaddition of the IWF in a relatively small amount compared toconventional washing systems. Specifically, an amount of approximatelysix (6) liters will be satisfactory for a normal size load of fabrics orclothes by conventional standards. The volume of IWF is less than atypical water volume for a conventional system since the surface tensionand textile absorption of the IWF fluid is significantly less than thatfor water. Following the introduction of the IWF at step 61, the fabric(i.e. clothes) and IWF are tumbled slowly for a short period of time atstep 62. Then, performance enhancers as discussed above, are added atstep 63 to remove targeted contaminants in the fabrics. Mechanicalenergy is then applied to the system for a relatively short periodcompared to conventional aqueous systems at step 64.

In preferred embodiments, the agitation time ranges from about 2 minutesto about 5 minutes. In most embodiments and methods of the presentinvention, there is no need for the agitation time period to exceed morethan 10 minutes. The combination of the draining of the IWF and a softspin is performed at step 65. Because the IWF has a density greater than1.0 g/ml and further because the IWF is not absorbed by the fabrics to alarge degree, most of the IWF simply drains away from the fabric.However, the application of a soft spin to the fabrics by rotating thewashing vessels shown at 16 in FIGS. 2 and 3 has been found effective toremove any excess IWF. The soft spin need not be as fast as a spinningcycle of a conventional washing machine that uses water. Instead, therotational speed is similar to that of a conventional dryer, thereforeeliminating the need for an elaborate suspension system as presentlyrequired by conventional washing machines.

The combination of the IWF and performance enhancers are captured atstep 66. Water is added to this mixture at step 67 to separate the IWFfrom the performance enhancers. Water will have a greater affinity forthe performance enhancers than the IWF. Further, the IWF is immisciblein water. Accordingly, a gravity separation technique can be employed atstep 68 due to the difference in the specific gravity of water and theIWF. Water and the performance enhancers are disposed of at step 69while the IWF is filtered at step 70 and stored at step 71 for the nextcycle. Air is introduced to the fabric at step 72 to complete the dryingof the garments without the need for an additional or separate dryingapparatus.

An alternative method is illustrated in FIG. 5 which includes adifferent recovery and separation process than that of the methodillustrated in FIG. 4. Instead of adding water to the IWF performanceenhancer mixture at step 67 and performing a gravity separation at step68 as illustrated in FIG. 4, the method illustrated in FIG. 5 practicesa fractional distillation separation at step 73. Specifically, after thecombination of the IWF and performance enhancers is captured at step 66,either the temperature of the mixture is increased to the IWF boilingpoint or the pressure is reduced to the point where the IWF begins toboil (or a combination of the two) at step 74. A fractional distillationof the IWF is performed at step 73, thereby separating the IWF from theperformance enhancers so that the IWF can be filtered at step 70 andstored at step 71. The performance enhancers are disposed of at step 69.

Yet another method is illustrated in FIG. 6 which begins with theloading of the washing apparatus at step 60. After the fabric is loaded,the first step in the method is the addition of a solvent mixturecomprising the IWF and a hydrophobic solvent at step 75. The hydrophobicsolvent is responsible for removing oily soils and oil-based stains. Thefabric load is tumbled for approximately 2-5 minutes at step 76. Acombination drain and soft spin step is carried out at step 77 wherebythe vast majority of the IWF and hydrophobic solvent mixture iscollected at a separation and recovery center at step 78 where a gravityseparation is carried out. Because the IWF is substantially heavier thanthe hydrophobic solvent, the two liquids are easily separated. The IWFis filtered at step 79 and stored at step 80. The hydrophobic solvent isfiltered and stored at step 81. After the IWF and hydrophobic solventare drained away from the fabric at step 77, a hydrophilic solvent isadded at step 82 to remove water soluble material and particulates. Acombination of the hydrophilic solvent and fabrics are tumbled for atime period ranging between 2 and 5 minutes at step 83. A combinationdrain and soft spin step is carried out at step 84. The bulk of thehydrophilic solvent is captured at step 85. Air is introduced into thewashing chamber at step 86 which results in the production of solventvapors which are condensed at step 87 and combined with the liquidsolvent at step 88 where the temperature of the contaminated hydrophilicsolvent is increased to its boiling point before being fractionallydistilled at step 89. Preferably, a coil is used to condense the vaporsat step 87 that has a sufficient length and temperature gradient tocondense all fluids simultaneously. The hydrophilic solvent, lesscontaminants, is filtered and stored at step 90 while the contaminantsare disposed of at step 91. It is anticipated that air introduced intothe washing chamber at a rate of approximately 1000 cubic feet perminute (CFM) will fully dry the fabric in a time period ranging fromabout three (3) minutes to about five (5) minutes, depending upon thespecific hydrophilic solvent utilized.

Turning to FIG. 7, an additional method of washing fabric in accordancewith the present invention is illustrated which again begins with theloading of the machine at step 60. A combination of IWF and hydrophilicsolvent are added to the fabric disposed in the washing chamber at step92. The fabric, IWF and hydrophilic solvent are then tumbled from a timeperiod ranging from two (2) to about five (5) minutes, and most likelyless than ten (10) minutes at step 93. A combination drain and soft spinprocess is carried out at step 94 which results in the collection of theIWF and hydrophilic solvent at step 95 where a gravity separation isperformed. The hydrophilic solvent is filtered, stored and saved at step96. The IWF is filtered at step 97 and stored at step 98 for re-use withthe hydrophilic solvent during the next cycle. Hydrophobic solvent isthen added to the fabric disposed within the washing chamber at step 99before a tumbling or agitation step is carried out at step 100 which,again, lasts from about two (2) to about five (5) minutes. A combinationdrain and soft spin step is carried out at step 101. The hydrophobicsolvent is captured at step 102, mixed with water at step 103 before agravity separation is carried out at step 104. The hydrophobic solventis filtered and stored for re-use at step 105 while the water andcontaminants are disposed of at step 106. Air is introduced to thewashing chamber at step 107 for drying purposes which will normally takefrom about three (3) to about five (5) minutes when the air isintroduced at a rate of about 1000 CFM.

Another method of practicing the present invention is illustrated inFIG. 8 which again begins with the loading of the machine at step 60. Inthe method illustrated in FIG. 8, the washing chamber is pressurized toabout 20 psi at step 107. A mist of IWF solvent is sprayed onto thefabric in the washing chamber at step 108 while the fabric is beingtumbled during the rotation of the washing chamber. The purpose ofadding the IWF in a mist form is to provide a greater surface areacoverage with less IWF volume. The increase in pressure minimizes theamount of vaporization of the IWF. The fabric is then subjected to aseries of spray jets which spray IWF onto the fabric at a rate of about10 ml/s at step 109. The application of the IWF under pressure throughthe jets at step 109 helps to dislodge particulates and other insolublematerial from the fabric. Co-solvents are added in a ratio ofapproximately 1:1 at step 110 before the combination of the fabric, IWFand co-solvents are tumbled at step 111 for a time period ranging fromabout two (2) minutes to about five (5) minutes. The pressure isdecreased at step 112 and the IWF solvents and contaminants are drainedoff and captured at step 113. The temperature of the mixture isincreased at step 114 to the lowest boiling point, either the IWF orco-solvent, and a fractional distillation is carried out at step 115.The co-solvent is filtered and stored at step 116 while the IWF isfiltered at step 117 and stored at step 118. The contaminants aredisposed of at step 119. Air is introduced into the washing chamber atstep 120 at about 1000 CFM for a time period ranging from about three(3) minutes to about five (5) minutes for drying purposes.

Another method of carrying out the present invention is illustrated inFIG. 9. The fabric or clothes are loaded into the machine at step 60.The cycle begins with a soft spin of the load at step 121. IWF andperformance enhancers are introduced into the washing chamber at step122, preferably through a spray nozzle. The IWF and performanceenhancers are collected and recirculated onto the fabrics at step 123.The spraying of the IWF and performance enhancers may last from a timeperiod ranging from about one (1) minute to about three (3) minutes.Additional IWF is added at step 124 to provide a transport medium forthe removal of oils and particulates. The load is agitated at step 125for a time period ranging from about three (3) minutes to about seven(7) minutes. A combination drain and soft spin procedure is carried outat step 126 and the washing chamber is heated at step 127 to vaporizeany remaining solvent on the fabric. The IWF and solvent is captured andcondensed at step 128, the pressure is decreased at step 129 to separatethe IWF from the performance enhancer. The IWF is condensed at step 130,filtered at step 131 and stored at step 132. The performance enhancersand contaminants are disposed of at step 133.

Another method of practicing the present invention is illustrated inFIG. 10. The machine is loaded with fabric at step 60. A combination ofdetergent and water is introduced into the washing chamber at step 135.The fabric, detergent and water combination is agitated for a timeperiod ranging from about six (6) minutes to about eight (8) minutes atstep 136. The IWF and at least one hydrophilic solvent are added at step137 for removing the water and transporting the particulates from theload. The IWF and hydrophilic solvent are miscible prior to theaddition, however, in the presence of water, they become immiscible andtherefore, upon capture of the IWF hydrophilic solvent and water at step138, the IWF can be separated using a gravity separation technique atstep 139. The IWF is filtered at step 140 and stored at step 141 whereit is combined with the recovered hydrophilic solvent. The hydrophilicsolvent is recovered by increasing water/hydrophilic solvent mixture atstep 142 to boil off the hydrophilic solvent at step 143 leaving thewater behind. The water and contaminants are disposed of at step 144.The hydrophilic solvent is then re-combined with the IWF at step 141.

Still referring to FIG. 10, ozone or ultraviolet (UV) radiation isapplied to the fabric at step 145 to assist in the bleaching and/ordisinfecting and/or odor removal of the fabric load. The ozoneconcentration should be greater than 500 ppm and the UV wavelengthshould fall in a range between 160-380 nm. As indicated at step 146, theload should be tumbling during the application of the ozone and/or UV.Air is then introduced for drying purposes at step 147.

Another method of practicing the present invention is illustrated inFIG. 11. The fabric load, or clothing, is hung at step 150 within asealed chamber. Performance enhancers are “fogged” into the chamber in avolume weight about equal to that of the fabric load at step 151.Instead of a typical agitation process, the clothing is shaken orvibrated for a time period ranging from about three (3) minutes to aboutfive (5) minutes. Ozone and/or UV may be applied to the clothing inappropriate amounts for stain removal and/or odor control at step 153.IWF is introduced into the vessel or cabinet at step 154 in a mist formand in an amount of about ⅓ the weight of the fabric and performanceenhancers. The cabinet temperature is then increased at step 155 tovaporize the performance enhancers and IWF. The performance enhancersand IWF mixture is captured at step 156 and fractionally distilled atstep 157. The IWF is filtered at step 158 and stored at step 159. Theperformance enhancers are disposed of at step 160.

Yet another method of practicing the present invention is illustrated inFIG. 12. The machine is loaded at step 161 and the vessel pressure isreduced to about 10 psi or below at step 162. As the IWF is being addedat step 163, the temperature of the vessel is increased to approximately40 C. which results in a steaming of the fabric or clothing with theIWF. The IWF vapors are condensed at step 164 preferably by a condenserdisposed at the top of the machine which then re-introduces thecondensed vapors back into the washing chamber for a time period rangingfrom about five (5) minutes to about ten (10) minutes, preferably whilethe clothes are being tumbled (see step 165). The clothes are thenshowered with a co-solvent at step 166 to remove particulates and oilysoils. The co-solvent, IWF and contaminants are captured at step 167,separated by centrifugal separation at step 168 before the contaminantsare disposed of at step 169. The co-solvent and IWF are separated atstep 170 by gravity separation before the co-solvent is filtered at step171. The showering of the co-solvent onto the garments may be repeatedat step 166, several times if necessary. The IWF is filtered at step 172and stored at step 173. The IWF that has been condensed at step 164, mayalso be captured at step 174 and filtered by the common filter at step172 and stored in the IWF storage vessel at step 173. The temperature ofthe vessel or chamber is increased at step 175 to fully dry the clothingbefore the pressure is increased to atmospheric pressure at step 176.

As noted above, one family of chemicals particularly suited for use asIWFs in the methods and apparatuses of the present invention are“fluoroinert” liquids. Fluoroinert liquids have unusual properties whichmake them particularly useful as IWFs. Specifically, the liquids areclear, colorless, odorless and non-flammable. Fluoroinerts differ fromone another primarily in boiling points and pour points. Boiling pointsrange from a about 56 C to about 253 C. The pour points typically rangefrom about 30 C to about −115 C.

All of the known fluoroinert liquids possess high densities, lowviscosities, low pour points and low surface tensions. Specifically, thesurface tensions typically range from 12 to 18 dynes as compared to 72dynes for water. Fluoroinert liquids typically have a solubility inwater ranging from 7 ppm to 13 ppm. The viscosity of fluoroinertstypically ranges from 0.4 centistokes to 50 centistokes. Fluoroinertsalso have high KB values, otherwise known as kauri-butanol values. TheKB value is used as a measure of solvent power of hydrocarbon solvents.High KB values indicate a relatively strong solvency.

In addition to fluoroinerts, hydrofluoroethers, perfluorocarbons andsimilarly fluorinated hydrocarbons can be used as an IWF in the methodsand apparatuses of the present invention. These additional workingfluids are suitable due to their low surface tension, low vapor pressureand high fluid density.

In the above methods, the cleaning agents or performance enhancers maybe applied to the fabric by way of an immersion process, misting,foaming, fogging, the application of a gel to the fabric, or the mixtureof a solid powder or solid particulates in the IWF. The machine loadingof the fabrics or clothes may be a bulk or batch process, a continuousprocess or, as noted above with respect to FIG. 11, the clothes may behung in a sealable chamber.

The removal of a film-type soil may be performed by vapor degreasing,increasing the temperature within the washing chamber, increasing the pHwithin the washing chamber, solubilization of the film-type soil, theapplication of enzymes to the film-type soil, the application ofperformance enhancers that break up the surface tension of the film-typesoil or performance enhancers that increase the viscosity of the IWF andtherefore increase the effectiveness of mechanical agitation in removingthe film-type soil.

Methods of removing particulate soil from fabrics in accordance with thepresent invention include attacking the soil with a working fluid havinga low surface tension and tumbling or agitating the working fluid andfabrics. Particulate soil may also be removed by spraying the fabricwith an IWF with a jet spray. Another effective method of removingparticulate soil in accordance with the present invention includesvibrating or shaking the fabrics and IWF inside the washing chamber.

Water soluble stains may be removed in accordance with the presentinvention by using water as a co-solvent, using performance enhancers toincrease the solubility of the stain in the IWF, shifting the pH of themixture in the washing chamber, shifting the ionic strength of themixing chamber and the washing chamber, increasing or decreasing theconductivity of the mixture in the washing chamber, and increasing ordecreasing the polarity of the mixture in the washing chamber.

Stains consisting primarily of protein may be removed in accordance withthe present invention with the use of enzymes, performance enhancersthat cause the protein to swell, performance enhancers that cleave theprotein, soaking the fabric in the washing chamber in IWF alone or IWFin combination with the performance enhancer and the use of lowtemperature tumbling and/or soaking.

Stains consisting primarily of carbohydrates may be removed inaccordance with the present invention by hydrating the stain by usingwater as a co-solvent, the use of enzymes, a shifting of the pH in thewashing chamber, an increase of the temperature in the washing chamberand performance enhancers that increase the solubility of thecarbohydrate stain in the IWF and/or co-solvent. Bleaching strategiesmay also be employed in accordance with the present invention.Bleachable stains may be removed by oxidation, reduction, the use ofenzymes, the use of performance enhancers to cleave color bonds and thepH may also be shifted within the washing chamber to remove a bleachablestain.

Surfactants may be removed from the fabrics in accordance with thepresent invention through use of dilution, force convection,vaporization, a solvent that is miscible with the surfactant,neutralization or phase inversion techniques.

As indicated above in FIGS. 4-12, tumbling of the fabric, IWF and anyadditives including performance enhancers and co-solvents in the washingchamber is a suitable method of transferring mass, i.e. soils, from thefabric to the IWF and/or co-solvent. Other methods of mass transferinclude rinsing, centrifugation, shaking, wiping, dumping, mixing andwave generation.

Also, as indicated above in FIGS. 4-12, the application of air is asuitable method of dehydration or drying the fabric. Other methods ofdrying may employ centrifugation, liquid extraction, the application ofa vacuum, the application of forced heated air, the application ofpressurized air, simply allowing gravity to draw the IWF away from thefabric and the application of a moisture absorbing material.

As indicated above in FIGS. 4-12, the IWF and co-solvents may berecovered through the use of gravity separation, filtration andcentrifugation. In addition, de-watering, scrubbing, vaporization, phaseinversion and the application of an induced electrical field may be usedin recovery and purification of the IWF and co-solvents.

As noted above, the tumbling, agitation or nutation may be accomplishedby generally rotating the washing chamber about a horizontal axis orabout a vertical axis. An example of a washing apparatus having agenerally horizontally disposed axis of rotation is set forth in U.S.Pat. No. 4,759,202, which is incorporated herein by reference. Oneexample of a washing apparatus having a generally vertical axis is setforth in U.S. Pat. No. 5,460,018, which is also incorporated herein byreference.

An apparatus that can be used to carry out the method set forth in FIG.11 is further illustrated in FIGS. 13 and 14. Specifically, theapparatus 200 includes a main housing or cabinet 201. The cabinet 201forms an interior region 202 for hanging garments 203. The door 204 isequipped with a gasket 205 for sealing the interface between the door204 and the main cabinet 201.

The cabinet 201 includes an upper assembly 206 which can include a meansfor shaking or vibrating the garments 203 (see step 152 in FIG. 11) aswell as adding ozone/UV or applying a mist to the garments 203 (seesteps 153, 154 in FIG. 11). The cabinet 201 also includes a lowerhousing assembly 207 which can support a moisture or misting generator208 and a heater 209 for increasing the temperature inside the cabinet201. The condenser, distillation apparatus, filter, storage tank anddisposal means (see steps 156-160 in FIG. 11) may be attached to thecabinet 201 and housed in a manner similar to the IWF storage unit shownat 12 in FIGS. 2 and 3.

From the above description, it is apparent that the objects of thepresent invention have been achieved. While only certain embodimentshave been set forth, alternative embodiments and various modificationswill be apparent from the above description to those skilled in the art.These and other alternatives are considered equivalents and within thespirit and scope of the present invention.

1. In automatic cleaning apparatus of the type having automatic controlsfor carrying out a proscribed method of cleaning; container means forreceiving fabric to be cleaned and working fluids; means for adding aprimary working fluid and a first co-solvent to said container means;means for applying mechanical energy to provide relative movementbetween the fabric load and the wash liquor in the wash container for atime sufficient to provide fabric cleaning; means for separating saidfirst co-solvent and primary working fluid from the fabric to becleaned; means for adding a second co-solvent to said container meansand adding mechanical energy to provide movement between wash liquor andfabric; means for separating said second co-solvent from the fabric tobe cleaned; and means for flowing air through said container means todry the fabric therein in situ.
 2. An automatic cleaning apparatus asdefined in claim 1, wherein said means for applying mechanical energycomprises means for moving the wash container in a manner which movesthe fabric load with respect to the wash liquor.
 3. An automaticcleaning apparatus as defined in claim 1, wherein said means forapplying mechanical energy comprises means for rotating the washcontainer about a horizontal axis.
 4. An automatic cleaning apparatus asdefined in claim 1, wherein said means for applying mechanical energycomprises means for rotating the wash container about a vertical axis.5. An automatic cleaning apparatus as defined in claim 1, wherein saidmeans for applying mechanical energy comprises means for nutating thewash container about a vertical axis.
 6. An automatic cleaning apparatusas defined in claim 1, wherein said means for applying mechanical energycomprises means for vibrating the wash container.
 7. An automaticcleaning apparatus as defined in claim 1, wherein said means forapplying mechanical energy comprises a plurality of high pressure jetsdisposed in said wash container and constructed and arranged to impailon the fabric to be cleaned.
 8. An automatic cleaning apparatus asdefined in claim 1, wherein said means for applying mechanical energycomprises a movable agitator mounted in the wash container.
 9. Anautomatic cleaning apparatus as defined in claim 1, wherein individualcontainers for the primary working fluid and co-solvent areself-contained in the cleaning apparatus.
 10. In an automatic cleaningapparatus of the type having automatic controls for carrying out aproscribed method of cleaning; container means for receiving fabric tobe cleaned and working fluids; means for adding a wash liquor to saidcontainer means; means for applying mechanical energy to providerelative movement between the fabric load and the wash liquor in thewash container for a time sufficient to provide fabric cleaning; meansfor separating said wash liquor from the fabric to be cleaned; means foradding a liquid extraction solvent to said container means and addingmechanical energy to provide movement between wash liquor and fabric;means for separating said liquid extraction solvent from the fabric tobe cleaned; and means for flowing air through said container means todry the fabric therein in situ.
 11. An automatic cleaning apparatus asdefined in claim 10, wherein said liquid extraction solvent is storedtherein separately from the working fluid.
 12. An automatic cleaningapparatus as defined in claim 10, wherein said liquid extraction solventis accomplished by spraying said liquid extraction solvent onto thefabric.
 13. In an automatic cleaning apparatus of the type havingautomatic controls for carrying out a proscribed method of cleaning: Acontainer for receiving fabric to be cleaned and fluids; Storage tanksfor each of a primary working fluid and a liquid extraction solvent; Adispenser adapted for selectively dispensing working fluid andselectively dispensing the liquid extraction fluid into said container;Means for applying mechanical energy to provide relative movementbetween the fabric load and the fluid in the wash chamber; Means forseparating fluids from the fabric to be cleaned; and Means for flowingair through said container to dry the fluids therein in situ.
 14. Anautomatic cleaning apparatus as defined in claim 13, wherein theapparatus contains a pump for delivering a fluid or additive from thedispenser to the container.
 15. An automatic cleaning apparatus asdefined in claim 13, wherein mechanical energy is imparted to fluid andfabrics through one of the following: tumbling, agitating, nutating or acombination thereof.
 16. An automatic cleaning apparatus as defined inclaim 13, wherein an additive is added to the container through adispenser.
 17. An automatic cleaning apparatus as defined in claim 16,wherein the additive is stored in a separate tank for dispensing.
 18. Anautomatic cleaning apparatus as defined in claim 13, wherein saidapparatus contains a means for controlling the sequential steps of:adding a working fluid and at least one washing additive to thecontainer; providing mechanical energy to the wash liquor and fabric toprovide relative movement between said wash liquor and fabric; removingsaid wash liquor from fabric; and separating working fluid from washliquor.
 19. An automatic cleaning apparatus as defined in claim 18,wherein said control means provides a co-solvent to the container. 20.An automatic cleaning apparatus as defined in claim 19, wherein saidcontrol means removes co-solvent from the fabric.
 21. An automaticcleaning apparatus as defined in claim 16, wherein said apparatusprovides a co-solvent to the container.
 22. An automatic cleaningapparatus as defined in claim 21, wherein the co-solvent is the liquidextraction solvent.
 23. An automatic cleaning apparatus as defined inclaim 21, wherein the co-solvent is selected from the group consistingof: perfluorocarbons, hydrofluoroethers, fluorinated hydrocarbons,carbon dioxide, fluoroinerts or mixtures thereof.
 24. An automaticcleaning apparatus as defined in claim 23, wherein the co-solvent isfurther selected from methoxynonafluorobutane, ethoxynonafluorobutane ormixtures thereof.
 25. An automatic cleaning apparatus as defined inclaim 21, wherein said apparatus provides an additional co-solvent tothe container.
 26. An automatic cleaning apparatus as defined in claim22, wherein said apparatus contains a separator for separating theliquid extraction fluid from the working fluid.
 27. An automaticcleaning apparatus as defined in claim 26, wherein said separator isselected from the group consisting of: gravity separation, filtration,centrifugation, fractional distillation, freeze distillation,adsorption, absorption, inducing electrical fields, vaporization ormixtures thereof.
 28. An automatic cleaning apparatus as defined inclaim 27, wherein said separator contains a means for disposing saidwashing additives.
 29. An automatic cleaning apparatus as defined inclaim 13, wherein said means for flowing air contains a means forheating said air.